PCI in Patients With 3VD: SYNTAX II Study Results
What is the impact of recent technical and procedural developments in percutaneous coronary intervention (PCI) on outcomes in appropriately selected patients with three-vessel (3VD) coronary artery disease?
The SYNTAX II study was a multicenter, all-comers, open-label, single-arm study that investigated the impact of a contemporary PCI strategy on clinical outcomes in patients with 3VD in 22 centers from four European countries. The SYNTAX-II strategy included: heart team decision making utilizing the SYNTAX Score II (a clinical tool combining anatomical and clinical factors), coronary physiology-guided revascularization, implantation of thin strut bioresorbable polymer drug-eluting stents, intravascular ultrasound–guided stent implantation, contemporary chronic total occlusion revascularization techniques, and guideline-directed medical therapy. The rate of major adverse cardiac and cerebrovascular events (MACCE; composite of all-cause death, cerebrovascular event, any myocardial infarction [MI], and any revascularization) at 1 year was compared to a predefined PCI cohort from the original SYNTAX-I trial selected on the basis of equipoise 4-year mortality between coronary artery bypass grafting (CABG) and PCI. As an exploratory endpoint, comparisons were made with the historical CABG cohort of the original SYNTAX-I trial. The outcome analyses were performed according to the intention-to-treat principle and are presented as Kaplan–Meier estimates and compared with Cox proportional hazards models.
Overall, 708 patients were screened and discussed within the heart team; 454 patients were deemed appropriate to undergo PCI. At 1 year, the SYNTAX-II strategy was superior to the equipoise-derived SYNTAX-I PCI cohort (MACCE SYNTAX-II 10.6% vs. SYNTAX-I 17.4%; hazard ratio [HR], 0.58; 95% confidence interval [CI], 0.39-0.85; p = 0.006). This difference was driven by a significant reduction in the incidence of MI (HR, 0.27; 95% CI, 0.11-0.70; p = 0.007) and revascularization (HR, 0.57; 95% CI, 0.37-0.9; p = 0.015). Rates of all-cause death (HR, 0.69; 95% CI, 0.27-1.73; p = 0.43) and stroke (HR, 0.69; 95% CI, 0.10-4.89; p = 0.71) were similar. The rate of definite stent thrombosis was significantly lower in SYNTAX-II (HR, 0.26; 95% CI, 0.07-0.97; p = 0.045).
The authors concluded that at 1 year, clinical outcomes with the SYNTAX-II strategy were associated with improved clinical results compared to the PCI performed in comparable patients from the original SYNTAX-I trial.
This open-label, nonrandomized study reports that PCI using the SYNTAX-II strategy was associated with superior clinical outcomes compared with the PCI arm of the original SYNTAX-I trial, with a lower incidence of MACCE driven by a reduction in MI, revascularization, and definite stent thrombosis at 1-year follow-up. Importantly, physiological assessment, which was feasible in 75% of lesions, contributed to deferring treatment in 25% of the interrogated stenosis. An exploratory analysis at 1 year suggests that PCI with the SYNTAX-II strategy was associated with similar clinical outcomes to the equipoise-derived SYNTAX-I CABG cohort. While the initial results of SYNTAX II provide evidence of the impact of the technological developments in the field of PCI on clinical outcomes, longer-term follow-up is indicated to determine whether the noninferiority of PCI using the SYNTAX-II strategy compared with CABG is maintained. A randomized clinical trial of contemporary PCI versus CABG will be needed to provide definitive evidence of equivalence.
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